Spring-bolt for door and other locks



UNITE ST i GEO. W. ROBINSON AND E. B. ROBINSON, OF BOSTON, MASSACHUSETTS.

SPRING-BOLT FOR DOOR AND OTHER LOCKS.

Specification of Letters Patent No. 1,626, dated .Tune 10, 1840.

To all whom t may concern Be it known that we, GEORGE WV. ROBINSON and EZBA B. ROBINSON, both of Boston, in the county of Sulolk and State of Massachusetts, have invented a new and useful Improvement in Spring-Bolts of Door and other Locks; and we do hereby declare the following to be a full and exact description thereof.

Our said improvement consists in inserting a bar of steel or other metal (which may be about a quarter of an inch square for an inside door lock and about seven eighths of an inch long, and larger or smaller for other locks in proportion) into a longitudinal slit in the projecting end of the spring bolt, the bar to project just as far from the box ofthe lock as the bolt does and to enter into the box at the other end just far enough to. turn upon a pivot, passing through the bar and through the bolt. The inner end of this bar is rounded off on the side which rests against the lock plate, and on the opposite side and between the pivot and the inner end of the bar is a transverse groove, into which the end of a flat spring -plays to bear the rounded corner down against the lock plate, and to elevate the opposite end of the bar which projects from the box at an angle of about forty-live degrees with the bolt. The other end of the fiat spring is fastened to the bolt nearer to the end which is connected with the knob by which the bolt is drawn back. The bar being thus elevated by the pressure of the spring upon the inner end of it, when the door shuts the end of the bar first comes in contact with the catch, and as the door closes the bar is pressed into the box, turning at the same time on the pivots and carrying the bolt in with it, without any friction against the catch, and the door is shut very easily and quietly.

A reference to the annexed drawing will make this description more intelligible.

The bolt may be thrown forward by a spiral or other spring in the usual manner,

but so adapted as not to interfere with the action Of the bar.

Figure l is a perspective View of the'bolt with the bar adapted to it, looking at it Sidewise, and the dotted lines represent the continuation of the parts where they are hidden from view by the other parts. rIhe letters represent the Same parts as in the Figs. 2 and 3, though seen in different directions. Fig. 2 is a separate view of the bar and flat spring. Fig. 3 is a simplified view of the bolt without the bar and flat spring.

In the several figures where they occur, A is that part of the bolt which projects beyond the box.

a, o, CZ are the front and back pieces of the box.

B is the bar.

C is the flat spring.

z', is the hole through the bolt and bar through which the pivot passes.,

j, is the place where the flat spring is fastened tO the bolt.

7c, 7e, are the projections by which the knob draws back the bolt.

L is the spiral spring by which the bolt is thrown forward, being coiled around a rod passing and playing through the projection of the bolt M.

N is the hole in the lock plate through which the shaft of the knob passes.

O, is the longitudinal slitin the bolt into which the bar is inserted.

that we claim as our invention and desire to secure by Letters Patent is-` The bar of metal turning on a pivot in the spring bolt and provided with a spring in combination with the spring bolt for the purpose and in the manner described.

In witness whereof we have hereto subscribed our naines this seventh day of May J. L. ENGLISH, FRANKLIN Dnxrnn. 

